The treatment for hypertension includes the drugs known as ANTIHYPERTENSIVE DRUGS these are used to lower the blood pressure on vessels 

• It is not a disease but considered as one of the potent risk factors which alters the cardiovascular performance 
• Almost all of the managing  guidelines include the level of hypertension to be 140 mm of Hg / 90mm of Hg.However ,few consider as 150mm of Hg/90mm of Hg for age old patients 
• Based on the normal range level hypertension is classified into Stages 

The risk factors that should be considered are

1. Age should be greater than 55 (men) ,more than 65( women)
2. Smoking or alcohol consumption
3. Diabetes mellitus
4. Cardiac diseases 
5. Sedentary lifestyle 
6. Obese
7. Family history  

• Pharmacological therapy is advised when initial managing therapies such as diet restrictions, physical exercises, underlying diseases are not manageable & benefiting the overall health condition 
•  

• The pharmacological approach for hypertension is divided into several classes based on the regulatory system at which level  it interferes .

Classification of drugs includes 

 (i) DIURETICS

Diuretics are drugs which reduces the plasma and extracellular fluid volume by 10-15% and this reduces cardiac output

(i) THIAZIDES

•           HYDROCHLOROTHIAZIDE AND                       CHLORTHALIDONE 

• They are considered as mild hypertensive drugs 

• hydrochlorothiazide and chlorthalidone have the similar efficacy and efficiency in controlling uncomplicated hypertension 
• The only discrepancy exists that  chlorthalidone is long acting(48hours) & have the better action  when compared with hydrochlorothiazide with action duration less than 24 hours
• The fall in blood pressure develops gradually over 3-4 weeks 
• No fluid retention and tolerance 
• Cost effective
• Has lesser side effects and diminished risk of osteoporosis,postural hypertension

•   INDAPAMIDE 

• it’s an mild diuretic chemically related to chlorthalidone 
• It is absorbed well orally 
• Metabolic effects are minimal at Hypertensive drug dosages 
• Side effects are infrequent

(ii) HIGH CEILING 

• Furosemide is a weaker hypertensive drug but a strong diuretic than thiazides
• High ceiling diuretics have the risk of side-effects including fluid-electrolyte imbalance ,weakness,intolerance etc 
• They are recommended in patients  with chronic renal failure + hypertension
• Alternatively can be prescribed in patients when fluid retaining vasodilators are used or Cardiac heart failure (refractory)
• The fall in Blood pressure is due to reduction in plasma volume and cardiac output

Several dose ranging studies reveals that the use of high dosage(>25mg/day) of diuretics causing some serious health troubles .They are 

1.muscle pain ,weakness ,fatigue due to decrease Potassium or hypokalemia 

2.carbohydrate intolerance

3.diabetes due to inhibition of insulin produce 

4.erectile dysfunction in men

5.gout due to inhibiting urate excretion 

6.rise in triglycerides and LDL with lowering up of HDL

7.increased incidence of cardiac death

• With low dosage of diuretics (<25mg/day)the above mentioned side effects seem to be reduced and minimal 

• If the low dosage of Diuretics fails to lower blood pressure to desired level then it is advised with the combination with or without potassium sparing  diuretics or else the dosage can be increased 

(iii) ALDOSTERONE ANTAGONIST

• Spironolactone and eplerenone reduces blood pressure 
• This class of drugs attenuate the aldosterone alternative actions
• Used in conjunction with thiazide diuretic because these drugs prevent K+loss 
• It has side-effects which are mainly related to hormones such as impotence ,menstrual irregularities
• Should keep eye on Hyperkalemia , especially when used in combination with ARBs and ACE inhibitors 

RENIN-ANGIOTENSIN SYSTEM INHIBITORS 

(i) ANGIOTENSIN CONVERTING ENZYME INHIBITORS(ACE)

• These class of drugs are effective even at lower doses and most tolerable 
• They are most appropriate antihypertensive in patients with other conditions such as Diabetes,nephropathy,CHF,Angina except bilateral renal artery stenosis
• It is more effective in younger than adults and whites are most beneficial 
• The common and only side effect is dry persistent cough and it should be discontinued
• Can be used alone or in combination with Diuretics/beta-blockers (to increase efficacy)

(ii) ANGIOTENSIN RECEPTOR BLOCKERS (ARB ‘s)

• The dosage of 50mg/day of losartan is an effective antihypertensive but with the newer drugs such as candesartan, telmisartan are much effective as ACE inhibitors
• The side effects associated with these drugs  are very rare because it don’t increase kinin levels 
• The Balck race has more advantage with the usage of ARB ‘s
• ARB ‘s are not supposed to combine with ACE’s 

(iii) DIRECT RENIN INHIBITOR

• Is mainly functions by blocking the renin catalytic activity and which inhibits the production of Angiotensin I & II
• Their use is only limited when there is an restricted use of ARB’ s or ACE inhibitors 

SYMPATHETIC INHIBITORS 

(i) BETA -ADRENERGIC BLOCKERS 

• Used mostly in stage I cases which is said to an mild hypertensive drug
• The action is well sustained after 3 weeks 
• Short half lives so it’s action maintains over 24 hours only
• There are several restrictions associated with cardiac diseases or pulmonary,peripheral vascular diseases  with the use of beta blockers 
• Side effects are non avoidable they are forgetfulness,libdio,increased use of antidepressants,fatigue etc
• Hypertension with stable heart failure cases can be treated with metoprolol + ACE inhibitors 
• Inferior effectiveness in cases of myocardial infarction or stroke no longer used as the first line of drugs 

(ii) ALPHA + BETA ADRENERGIC BLOCKERS 

• LABETALOL

• It acts faster than the beta blockers
• Oral use of labetalol is not recommended in moderately severe hypertension who are not responding to beta blockers because of side effects associated with it 
• It can also be used as i.v for rapid reduction of B.p in case of pre/eclampsia,clonidine withdrawal or hyperadrenergic conditions 

• CARVEDILOL

• It is a non selective beta + selective alpha blocker with vasodilating activity 
• Frequently used drug in cases of Hypertension , cardiac heart failure 
• It has superior properties than labetalol with the same side effects

(iii)ALPHA-ADRENERGIC BLOCKERS

• PRAZOSIN

• Moderately potent antihypertensive drug
• They are initially advised with low dosages (0.5mg/day) then continued  by gradually increase the dosage of not patient may have first dose effect 
• Given mostly at bedtime ,twice daily 
• Have 3 hours of half life with its action which last for nearly 10-13 hours 
• Adverse effects include postural hypertension,headache,weakness,day mouth, palpitations etc 
• Due to fluid retention,CHF is precipitated  
• May be used in conjugation with Diuretics +beta blockers 

Non selective alpha blockers 

Such as phentolamine,phenoxybenzamine used for special purposes like cheese reactions,clonidine withdrawal pheochromocytoma etc

(iv) CENTRAL SYMPATHOLYTICS 

• CLONIDINE

• It is moderately potent antihypertensive 
• It is an derivative of imidazoline
• It is taken orally and action lasts for 10-24 hours  
• Has high affinity and intrinsic activity at alpha 2  subtype receptor at brain stem
• Adverse effects include postural hypertension,sedation,impotence ,bradycardia,salt and water retention etc 
• Occasionally used in combination with Diuretics 
• Other properties are analgesic ,accentuates the symptoms of menopausal syndrome,control motions  in case of diabetic nephropathy patients

• METHYLDOPA

• It is a selective alpha 2 agonist

• It is used for pregnancy hypertensive women
• Side effects include lethargy,sedation,impotency,Dry mouth ,weight gain ,mild postural hypertension 
• Not commonly used but can given in combination with Diuretics 

VASODILATORS 

ARTERIOLAR DILATOR 

• HYDRALAZINE

• Used as 2nd line drug with Diuretics and beta blockers
• Can be suggested in pregnancy women, especially with preeclampsia 
• Contraindicated in older age patients , ischemic heart condition
• Can be consumed orally or by i.m
• Adverse effects are frequent .angina, palpitations,tremors,paresthesia,muscular cramps  etc

ARTERIOLAR+VENODILATOR 

•    SODIUM NITROPRUSSIDE

• Rapid acting vasodilator
• Used as a 2nd line drug for Hypertension
• It improves ventricular function and cardiac output 
• Side effects include palpitations,weakness,abdominal pain,lactic acidosis 

CALCIUM CHANNEL BLOCKERS

• The onset of action is quick and rapid 
• Used as a first line drug in patients with chronic renal disease 
• They are not usually contraindicated in asthma,angina conditions
• Can be used during pregnancy & in elders 
• With infrequent side effects than other class of drugs 
• Short acting CCB’ s are not recommended as Hypertension medication

TREATMENT 

the ultimate treatment goal is to reduce mortality and morbidity associated with the rise in blood pressure without inconvenience to patient 

If untreated the likelihood of target organ damage happens like

Coronary artery disease 

Hypertensive heart disease 

Stroke

Encephalopathy 

Glomerulopathy

Aneurysm of aorta 

Renal failure 

If the patient has already persistent tissue organ damage then severity of risk is much more worse to death

Possible combinations of drugs 

• Firstly a single drug is advised ,later on other drugs of different groups are added according to the patient condition demand and the expert following guidelines

• A stepped care approach should be followed initially 

• If Age of the patient is  <55 with non-black race/white race then 

 Step 1 : A mono drug is advised 

Step 2 : If the target level is not reduced or still no change then the combination of ACE INHIBITORS or ARB ‘s are added to the regimen

Step 3 : All the 1st line drugs with +ACE or ARB’ S are advised (3rd drug) .the dosages are adjusted to minimal levels 

Step 4 : When the condition still persists then he/she would likely have resistant hypertension that means a 4th needed to be added .This condition requires further evaluation.

• If the Age is >or equal to 55 ,black race then 

Calcium channel blockers(CCB’ s) or diuretics are recommended 

Combinations to avoid 

1.Alpha or beta adrenergic blockers +clonidine 

2.Hydralazine +prazosin

3.ACE-I + ARB

4.Methyldopa+clonidine

5.Beta blocker +diuretics 

• Drugs to be used during pregnancy

These drugs has long history of safe usage during pregnancy ,preeclampsia with good effects  

                Labetalol -widely used now 

               Nifedipine -should stop before labor & still used now 

              Hydralazine -less frequently used now

              Methyldopa -still used 

• Drugs to be avoided during pregnancy 

ACE inhibitors,ARB’ s 

Diuretics

Nitroprusside Na.

Non-selective beta blockers 

HYPERTENSIVE EMERGENCIES( reduction of blood pressure within minutes) OR URGENCIES(in hours)

1.myocardial infarction with Hypertension 

2.Hypertensive encephalopathy

3.Pulmonary edema

4.Acute renal failure with hypertension

5.Eclampsia

6.Few others such as cheese reactions, pheochromocytoma, clonidine withdrawal 

Parenteral drugs are used in emergencies where as , Oral drugs are used in urgencies